Beer is the most consumed alcoholic beverage globally, and the demand for differentiated beers with peculiar characteristics has intensified among beer consumers, creating a significant market niche. In this study, we developed a low alcohol light craft beer enriched with olive leaf extract (Olea europaea L.). The cold mashing technique associated with interrupted fermentation was used in the mashing step. Different concentrations of olive leaf extract (0.5, 1.0 and 2.0%) were added at the maturation stage. The samples were characterized by physicochemical parameters, phenolic and polyphenolic content, bioactive compounds, antioxidant potential, and microbiological quality.

The cold mash technique associated with interrupted fermentation provided a low-alcohol beer (≅ 1.3%). The bitterness dimension (19.0 to 23.2 IBU) and color (9 – 17 EBC) parameter were in accordance with the Beer Judge Certification Program (BJCP) for the American Blond Ale-style. The addition of the extract enriched the content of total phenolics (171.09 to 437.4 mg GAE/mL) and polyphenolic (221.4 to 729.0 mg/L). Coumaric, ferulic, and cinnamic phenolic acids were detected in appreciable amounts in the beers. Oleuropein was the major compound in the beverage and plant extract. After adding 2% extract, the ABTS and DPPH radical scavenging activity, as well as the ferric reduction power, increased in beers by 28.4%, 449.1%, and 120.5%, respectively.

The extract of O. europaea L. promoted the enrichment of low-alcohol beer samples with bioactive compounds and antioxidant potential. The results obtained indicated the potential use of O. europaea L. extract as a natural oxidant in other beverages and food products.